TR Canthar. an old pharmacy bottle circa 1900

CANTHARONE?, Cantharidin, Cantharides, Cantharis vesicatoria,
CANTHARONE ®, Cantharidin Collodion;

Composition: 0.7% cantharidin in a film-forming vehicle containing acetone, ethocel and flexible collodion. Ether 35%, alcohol 11%.

Indications: Cantharone is intended for removal of benign epithelial growths: warts (including ordinary, periungual, subungual, plantar and palpebral warts) and molluscum contagiosum. It is designed for topical application by or under the supervision of a physician. Its simplicity and the absence of instruments and manipulation commend Cantharone to the physician treating children. Advantages: Simple and painless to apply. No advance preparation. No knives, needles or cauteries. Leaves no scar because it is selectively destructive; does not affect tissue layers below the epidermis; contains no randomly destructive acids. Clinically proved effective. Directions: Ordinary and periungual warts—No cutting or prior treatment is required. (Occasionally nails must be trimmed to expose subungual warts to medication.) Apply Cantharone directly to the lesion; cover the growth completely using an applicator stick. Allow a few seconds for a thin membrane to form and cover with a piece of non-porous plastic adhesive tape, e.g., Blenderm. Instruct patient to remove tape in 24 hours and replace with a loose Band-Aid. On next visit remove necrotic tissue and reapply Cantharone to any growth remaining. Defer second treatment if inflammation is intense. A single application usually suffices for normally keratinized skin. Plantar warts—Pare away keratin covering the wart; avoid cutting viable tissue. Using an applicator stick, apply Cantharone to the wart, repeating until a generous amount has been applied. Allow to dry until a film forms, then apply a protective cut-out cushion and secure with non-porous plastic adhesive tape (Blenderm). Leave in place for a week, then debride. If any viable wart tissue remains after debridement, reapply a small amount of Cantharone and bandage as above. Three or more such treatments may be required for large lesions. When destruction of wart is complete, the healed site will appear smooth, with normal skin lines.

Palpebral warts—Using a toothpick or fine probe, apply a small amount of Cantharone to the surface of the wart. Avoid touching surrounding normal skin or applying inside the eyelashes. Leave lesion uncovered. Repeat in a week or ten days if any growth remains. Molluscum contagiosum—Coat each lesion with a thin film of Cantharone. In one week, treat any new lesions the same way and retreat any resistant lesions with Cantharone, this time covering with a small piece of occjusive tape. The tape should be removed in 6 to 8 hours.

Warnings: Cantharidin is a strong vesicant and Cantharone may produce blisters if it comes in contact with normal skin or mucous membrane. If spilled on skin, wipe off at once, using acetone, alcohol or tape remover. Then wash vigorously with warm soapy water, and rinse well. If spilled on mucous membranes or in eyes, flush with water, remove precipitated collodion, and flush with water for an additional 15 minutes.

Patients vary in their sensitivity to cantharidin and in rare cases tingling, burning.or extreme tenderness may develop. In these cases the patient should remove tape and soak the area in cool water for 10 to 15 minutes, repeating as required for relief. If soreness persists, puncture blister using sterile technique, apply antiseptic and cover with a Band-Aid. It is advisable to treat only one or two lesions on the first visit, until the sensitivity of the patient is known. For external use only. Adverse Reactions: The development of annular warts following Cantharone therapy has been reported in a small percentage of patients. These lesions are superficial and, although they may alarm some patients, present little problem. Treatment consists of patient reassurance and retreatment using either Cantharone or other procedures. There has been one report of chemical lymphangitis following use of Cantharone in combination with salicylic acid plaster. How Supplied: 7.5 ml bottles.

Taken from package insert of CANTHARONE®,1986.